Added a new form for Entrees
Integrated Entree form into templates, simplified tests
Renamed all references to id_new_entree and entree_name to use their
form equivalents, id_name and name (currently broken)
Integrated Entree form into all views (working again)
Made Entree form able to save to proper Arsenal
Added duplicate entree validation and improved string representation
Added form to handle adding entrees to existing arsenal. Simplified model tests.
Updated arsenal view to use the ExistingArsenalEntreeForm
Added South as a dependency
Created initial South migration to match live
Added new migration for arsenal entree uniqueness constraint